Apple tree ‘Kitaro’

ABSTRACT

Disclosed is an apple tree having a medium vigor, rounded and crenated leaves, exhibiting excellent resistance to Alternaria blotch and bearing a medium size fruit maturing mid-season and having high productivity with an slightly heavy preharvest fruit drop. The fruit has an oblate shape, has yellow colored skin and has excellent storage quality. The flesh of the fruit is yellowish white, juicy and firm, and further, has a strong sweetness and medium sourness, thereby providing a good sweet-sour balance and rich taste, and has an excellent eating quality.

BACKGROUND OF THE VARIETY

The present invention relates to a new and distinctive variety of appletree belonging to a medium-maturing apple cultivar and, moreparticularly, relates to an apple variety having high quality and highresistance to disease and insect, for eating raw and for processing.

Regarding medium-maturing apple varieties, although ‘Jonathan’ and‘Starking Delicious’ were widely cultivated in the past, they havebecome unpopular due to their taste and poor storage quality, and thereare no main medium-maturing apple varieties now known to us. Thus it wasnecessary to breed a main medium-maturing apple variety immediately.

Accordingly, the present breeders crossed ‘Hatsuaki’, which is anexcellent variety for both eating raw and for processing, with ‘Fuji’,which is a main economical variety, to obtain excellent medium-maturingapple varieties having good fruit quality and high productivity. Namely,the purpose of the invention is to avoid russet on fruit surface and toimprove the storage quality of the medium-maturing variety ‘Hatsuaki’and to breed a new and distinct variety of medium-maturing apple varietyhaving excellent disease and insect resistance for eating raw and forprocessing.

ORIGIN AND ASEXUAL REPRODUCTION OF THE VARIETY

To accomplish this purpose, the breeders crossed ‘Fuji’, which had beencultivated at the Morioka branch of the Fruit Tree Research Station(currently the Apple Research Center, the National Institute of FruitTree Science), in Japan, and ‘Hatsuaki’ in 1976 and obtained seeds. Theseeds obtained were utilized for sowing and raising seedlings at saidbranch, in 1977, and the resulting seedlings were then grafted on ‘M27’,the most dwarfing rootstock, to accelerate bearing in 1978, and 127individuals were set in 1980.

The trees bore fruit in 1984 and one was selected in the primaryselection as a good medium-maturing individual in 1986. The presentinvention is directed to an apple tree ‘Kitaro’, which is one individualfrom among the 127 individuals derived from the cross ‘Fuji’ (♀) (theseed parent) and ‘Hatsuaki’ (♂) (the pollen parent), and was given anindividual number “512” during testing. Then the tree was selected as afavorable line of trees, which have a line name Ringo Morioka 52 Go,have been provided for local adaptability tests since 1991, and wereexamined to determine the various characteristics thereof, over a periodof eight years from April 1989 to March 1997. As a result, it was foundthat, for example, fruit of the trees had the desired characteristics,such as quality, storage quality and yield, as a medium-maturing applevariety, and the tree was distinguishable from the parent varieties,‘Fuji’ and ‘Hatsuaki’, as well as a control variety ‘Golden Delicious’.Accordingly, the breeders denominated this variety as ‘Kitaro’, inaccordance with this invention. The genus and species of the tree is‘Malus×domestica’.

Of the varieties, ‘Fuji’ is a variety generated from a cross between‘Ralls Janet’ and ‘Delicious’.

Of the varieties, ‘Hatsuaki’ is a variety generated from a cross between‘Jonathan’ and ‘Golden Delicious’.

The breeders asexually reproduced this new and distinctive variety ofapple tree ‘Kitaro’, by grafting on rootstock ‘M.27’ (U.S. Plant Pat.No. 3,793), at a number of Fruit Tree Research Stations in Morioka City,Iwate prefecture, Japan, and confirmed the homogeneity and stability of‘Kitaro’ according to the present invention. The instant plant retainsits distinctive characteristics and reproduces true to type insuccessive generations.

Of the above varieties, only M.27 is known to us as having been patentedin the United States.

An application for this new variety of apple tree, ‘Kitaro’ under theSeeds and Seedlings Law of Japan, was filed on Apr. 11, 1997, under thefiling number 9766.

The original tree of this apple tree is held at the Apple ResearchCenter of the National Institute of Fruit Tree Science, Ministry ofAgriculture, Forestry and Fisheries, residing at 92 Nabeyashiki,Shimokuriyagawa, Morioka City, Japan.

SUMMARY OF THE VARIETY

This new variety of apple tree, having medium vigor, is spreading, andmany spurs and axillary buds are formed.

The leaves of the tree are elliptic and serrated.

At Morioka City, Iwate prefecture, Japan, the trees have a floweringtime around May 21th. As the type of S gene of the present variety is(S3, S9), the cross-compatibility with common cultivars except‘Hatsuaki’ and ‘Sekaiichi’ is high.

There is slightly heavy preharvest drop of fruit and the present varietyexhibits high productivity. Regarding the main diseases, the tree isresistant to Alternaria blotch, but is susceptible to scab. It has notbeen recognized so far that any disease or insect except for the above,is significant.

The ripening of the present fruit occurs in mid October at Morioka,later by about one week than ‘Senshu’, and earlier by one week than‘Golden Delicious’. The size of the fruit is medium and averages about250-270 g, the same as ‘Senshu’. Although the type of ground color ofthe skin of the fruit is yellow (6D by RHS) and that of the over-coloris red-purple (63C by RHS), the surface of the skin, receiving sunlightis colored with dull pink. The shape of the fruit is oblate and theamount of the russet on the skin is high, thus the appearance of thefruit is not good. Depending on the years, cracking occurs in the stalkcavity of the fruit.

The flesh of the present fruit contains much sugar, about 15-16% Brix ofthe total sugar, and about 0.5 g/100 ml of malic acid, and further theflesh is firm and juicy, has a strong sweetness and medium sourness andprovides a good sweet-sour balance and rich taste. The storage qualityof the fruit is excellent, and is about 15 days at room condition andmore than 90 days in cold storage.

Compared with the seed parent, ‘Fuji’, the present variety isdistinguishable in that ripening of the fruit is earlier by about 20days than that of ‘Fuji’, the type of over color of the skin of thepresent variety is yellow, whereas that of ‘Fuji’ is colored withdeep-reddish stripe, and the fruit of the present variety does not havetendency to an inclination of the axis, as does ‘Fuji’.

Compared with the pollen parent, ‘Hatsuaki’, the present variety isdistinguishable in that flowering is earlier by several days and theripening of the fruit is later by about 10-15 days than that of‘Hatsuaki’, the color of the skin is yellow, whereas that of ‘Hatsuaki’is reddish-orange, and the flesh of the present variety is firm, and thestorage quality is excellent.

Compared with ‘Golden Delicious’, the present variety is clearlydistinguishable in that the ripening of the fruit is earlier by aboutone week, and there is preharvest drop of the fruit, the shape of thefruit is flatter than that of ‘Golden Delicious’, the flesh is firm andthe storage quality is excellent.

The color references presented are herein taken from The RoyalHorticultural Society Color Chart (R.H.S.) except where general terms ofordinary significance are used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a photograph of a tree shape of the new variety of apple treegrafted on ‘M.9’ (8 years old);

FIG. 2 gives the pedigree of the new and distinct variety of the appletree ‘Kitaro’;

FIG. 3 is a photograph of adult leaves (upper and under side) of the newvariety of apple tree;

FIG. 4 is a photograph of the flowers (opened and unopened) of the newvariety of apple trees.

FIG. 5 is a photograph of the fruit on the tree of the new variety ofapple tree;

FIG. 6 is a photograph of a side view, longitudinal-sectional view, andbasin of the fruit of the new variety of apple tree;

FIG. 7 is a photograph of a longitudinal-sectional view of the fruit ofthe new variety of apple tree; and

FIG. 8 is a photograph of a cross-sectional view of the fruit of the newvariety of apple tree.

DESCRIPTION OF THE VARIETY

The characteristics of the new and distinct variety of apple tree Kitaroare as follows (10-year-old tree investigated in Morioka City, Iwateprefecture, Japan):

Tree:

Tree height.—361 cm (atypical, as top of tree was cut to make treeeasier to work with.

Tree diameter.—3.76 m. Trunk diameter (30 cm above soil level): 9.7 cm.

Bark coloration.—Gray-brown (199D).

Crotch angles.—67.3°.

Texture of branch.—Slightly rough.

Coloration of branch.—Gray-brown (199D).

Habit of branches.—Medium and spreading, same as ‘Golden Delicious’.

Length of four-year-old branch.—166 cm.

Diameter of middle of four-year-old branch.—12.9 mm.

Length of one-year-old shoot.—40.0 cm.

Diameter of one-year-old shoot.—4.0 mm.

Time to produce a fruit-bearing tree.—4 years in Morioka City, Iwateprefecture, Japan.

Length of internode (one-year-old shoot).—Short (average 2.8 cm).

Size of lenticels (one-year-old shoot).—Length 1.60 mm, width 0.60 mm.

Number of lenticels (one-year-old shoot).—11.7/cm² (numerous).

Pubescence of shoot.—Sparse.

Bearing habit of fruit.—On spur. Number of axillary flower bud: about3.5/shoot.

Leaf:

Shape of leaf blade.—Elliptic, whereas that of ‘Golden Delicious’ isbetween rounded and long.

Margin.—Serrated.

Size of leaf (length).—Short (length average 8.4 cm, wide average 5.2cm).

Color of leaf.—Upper surface green (133A) and under surface green(138C).

Leaf apex.—Acuminate.

Leaf base.—Cuneate.

Venation pattern.—Venose.

Shape of stipules.—Sickle.

Size of stipules.—Short (length 10.8 mm, width 2.2 mm).

Color of stipules.—Upper surface green (133A), under surface green(138C).

Size of petiole.—Medium (length 25.5 mm, diameter 1.8 mm).

Color of petiole.—Yellow-green (150D).

Flowers:

Number of flowers (per cluster).—Medium (4-6).

Size (open flower).—Medium (diameter 51 mm).

Color (unopen flower).—Red-purple (65B).

Shape of flower bud.—Ovoid.

Size of flower bud.—Length 12.6 mm, diameter 8.8 mm.

Color of flower bud.—Red-purple (58C-65C).

Shape of petal.—Ovoid, whereas that of ‘Golden Delicious’ is oval.

Number of petals.—Medium (5).

Size of petals.—Length 26.2 mm, width 18.0 mm.

Shape of petals.—Apex obtuse, base mucronate.

Margin of petals.—Entire.

Texture of petals.—Soft.

Color of petals.—Upper surface white (155D-69D), under surfacered-purple (63D-65D).

Number of stamens.—Medium.

Color of anthers.—Light yellow.

Amount of pollen.—Much.

Color of pollen.—Yellow (7A).

Number of sepals.—5.

Size of sepals.—Length 9.5 mm, width 3.9 mm.

Shape of sepals.—Sharp pointed, apex acute (bases of sepals are linkedtogether).

Color of sepals.—Upper surface green (139D), under surface green (138D).

Fruit:

Size.—Length 69.7 mm, diameter 86.3 mm.

Shape.—Oblate, whereas that of ‘Golden Delicious’ is short-roundconical.

Crowing at eye end.—Medium, that of ‘Golden Delicious’ is weak.

Aperture of eye.—Open.

Depth of basin (eye end).—Medium, (12 mm), that of ‘Golden Delicious’ isdeep.

Diameter of basin (eye end).—Broad (38 mm), that of ‘Golden Delicious’is narrow.

Depth of stalk cavity.—Medium (18 mm), same as ‘Golden Delicious’.

Diameter of stalk cavity.—Broad (34 mm), whereas that of ‘GoldenDelicious’ is medium.

Size.—Small (about 250-270 g).

Type of ground color.—Yellow (6D), whereas that of ‘Golden Delicious’ islight yellow.

Type of over color of skin.—Red-purple (63C), whereas that of ‘GoldenDelicious’ is light yellow.

Amount of over color of skin.—5-10%.

Form of over color of skin.—Solid (undistinguished stripe).

Position of russet.—Overall.

Amount of russet.—Less than 5-10%.

Raised russet lenticels.—Present.

Size of lenticels.—Medium (diameter 1.3 mm), whereas that of ‘GoldenDelicious’ is large.

Number of lenticels.—Medium (2.3/cm²).

Silvery mottle of skin.—Absent.

Luster of skin color.—Not shiny.

Greasiness of skin.—Medium, more than ‘Golden Delicious’ but less than‘Jonagold’ when touched with the hand.

Bloom of skin.—Absent.

Cracking tendency of skin.—The skin has a tendency to crack, whereasthat of ‘Golden Delicious’ does not.

Surface texture of skin.—Rough, rougher than ‘Golden Delicious’.

Length of stalk.—Medium (about 3.0 cm).

Diameter of stalk.—2.4 mm.

Distinct swelling at end of stalk.—None.

Shape of core.—Conical.

Size of core.—Small, (length 31.0 mm, diameter 30.3 mm).

Number of core cells.—Medium (5 core cells) (loculus).

Color of flesh.—Yellow (11D).

Bruising of flesh.—Difficult, whereas that of ‘Golden Delicious’ iseasy.

Browning of flesh.—Strong, stronger than that of ‘Golden Delicious’.

Firmness of flesh.—Firm, firmer than that of ‘Golden Delicious’.

Texture of flesh.—Coarse, coarser than that of ‘Golden Delicious’.

Water core.—None or weak.

Sweetness of flesh.—Strong (Brix 15-16%), sweeter than ‘GoldenDelicious’.

Acidity of flesh.—Medium (about 0.5 g/100 ml).

Astringency of flesh.—None.

Flavor of flesh.—Similar to that of ‘Fuji’. Juiciness of flesh: Juicy.

Seed:

Total number of seeds.—7.0 per apple.

Number of fully developed seeds.—7.0 per apple.

Number of perfect seeds.—7.0 per apple.

Shape.—Ovoid.

Size.—Large (length 9.6 mm, width 5.8 mm).

Color.—Gray-orange (166A).

Physiological and ecological characteristics:

Date of germination.—Late (around April 10^(th) in Morioka City, Iwateprefecture, Japan), later than that of ‘Golden Delicious’.

Season of flowering.—Late (first day of bloom May 16th, day of fullbloom is around May 21st, and last day of bloom is May 25th, in MoriokaCity, Iwate prefecture, Japan), later than that of ‘Golden Delicious’.

Time of fruit harvest.—Medium (first day October 9th, peak period aroundOctober 13 to 19th, and last day October 20th in Morioka City, Iwateprefecture, Japan), earlier than that of ‘Golden Delicious’.

Amount of fruit harvest.—24.2 Kg per plant.

Time of fructification.—Precocious.

Self-fruitfulness.—0%. (Fructification by self-pollination).

Early dropping of fruit.—None or slight.

Preharvest dropping of fruit.—Heavy.

Physiological disorder of fruit.—Medium, cracking on part of the stalkcavity. Storage quality of fruit (room condition): Long (about 15 days).Storage quality of fruit (cold storage): Very long (about 90 days).Occurrence of heart rot (core rot): None or weak. Resistance toAlternaria blotch: Strong; stronger than ‘Golden Delicious’.

Culture: As the preharvest drop of the fruit of the new cultivar isslightly heavy, it is necessary to pay attention to optimum picking timeand to avoid late picking.

What is claimed is:
 1. A new and distinct cultivar of Apple plant, asillustrated and described.